1. Preheat oven to 350°F. Mix brown sugar and pumpkin pie spice in large bowl. Add sweet potatoes; toss well. Spread in 13x9-inch baking dish.
2. Mix orange juice and vanilla; pour over sweet potatoes. Dot with butter. Cover.
3. Bake 40 minutes. Remove from oven and stir. Bake, uncovered, 15 to 20 minutes longer or until sweet potatoes are fork tender.
Make Ahead: Sweet potatoes can be prepared up to 3 hours; reheat before serving.
Test Kitchen Tip: If baking with turkey in a 325°F oven, bake for 45 minutes. Remove cover and bake additional 15 to 20 minutes.